Steam-generator



(No Model.)

T. & J. CLIFFORD.

STEAM GENERATOR.

No; 244,186. Patented July 12,1881;

N. PETERS Fholo-Lithogmpher. Wnihmgion, 11cv UNITED STATES PATENT Fries,

THOMAS CLIFFORD AND JAMES CLIFFORD, OF MOUNT SAVAGE, MARYLAND.

STEAM-GENERATO R.

SPECIFICATION forming part of Letters Application filed March 1, 1881.

"Steam-Generators; and we do hereby'declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

Our invention relates to improvements in steam-generators in which a fire-box is made to form a part thereof; and the object of our improvementis to provide a combined bridge-wall and an arch for steam-generators which shall protect the tube-sheet from the intense heat of the fire in the furnace and at the same time make provision for the introduction of air to the space in said wall upon both its front and rear surface, below the surface of the grates, and for directingit to a point where it shall be thoroughly mingled with the gaseous products of combustion before they enter the tubes. We attain this object by the use of the devices illustrated in the accompanying drawings, in which- Figure 1 is a sectional elevation of a portion of a tubular steam-generator having a firebox attached to it and constituting a part thereof, showing a hollow or perforated bridge-wall and a hollow or perforated arch for deflecting the current of the gases and for heating air; and Fig. 2 is a transverse sectional elevation thereof on line to w of Fig. 1.

Similar letters of refer to similar parts in both of the figures.

Theimportance of protecting the tube or flue sheet of steam-generators from the intense heat of the burning fuel, and also of deflecting the gases arising from such fuel and thus giving them a greater run for the purpose of retainin g them for a longer period of time in contact with the heatingsurfaces of the fire-box, as Well as the desirability of mingling with such gases a fresh supply of air, is well known and generally admitted; and it is equally well known that various attempts have been made to accomplish all of these objects, as is illus- Patent No. 244,186, dated July 12, 1881.

(No model.) i

trated in the following-named patents Gill and Grier, March 13, 1860, No. 27,442; J Malioney, March 9, 1880, No. 225,402; and English Patent No. 1,902 of 1875; but such attempts have generally failed on account of the methods adopted for producing the results aimed at, such methods usually necessitating a variety of separate devices, which have been applied at different points and hence have not worked in common.

In carrying out our invention and for the purpose of producing the results above named we provide a novel device which is capable of producing beneficial results when the two parts of which it is composed are used separately, but which, when these parts are combined, will produce all of the above stated desirable results, said devices consisting of a hollow or perforated bridge-wall, A, placed in the furnace or fire-box of a steam-generator a short distance from the tube or fine sheet thereof, as shown in Fig. 1, and so as to leave between it and the tube-sheet a hot-air chamber, B. This bridge-wall is to be made hollow, as shown; or, instead of the wide space shown in it, a series of holes may be made throughit, which will have the desired efiect. It may be made of such material as fire-bricks are made of, or it may be of cast-iron or any other refractory material that will not be injuriously affected by the heat, its width to be equal, or about equal, to the width of the fire-box, to which it may be secured in any convenient manner. The grates O terminate at its front side, and consequently no part of the burning fuel can come in contact with that portion of the tubesheet which is in the rear of it; neither can the heat upon that portion of said tube-sheet become so intense as to destroy it, it being thoroughly protected by the wall A.

arrows in Fig. 1, and passes to the space or perforations A formed therein, and thence upward to its outlet into the fire-box, in doing which it becomes thoroughly heated, and in that condition is commingled with the gases arising from the fuel on the grate, by which means their combustion is facilitated and in sured before or at the time of their entrance into the tubes or flues. This part of our device may be advantageously used without being combined with the remainder; but for the purpose of realizing the full benefitof our invention we propose to connect with it a hollow arch,D, of equal, or nearly equal, width with the bridgewall and, by preference, of the curved form showninFig.2,itbeinginclined as thereshown. This arch, when used, may be madein one piece with the bridge-wall, or it maybe separate and connected thereto in any suitable manner, the parts being so arranged as to cause the opening or openings for the passage of air to register with each other and to cause them to form an angle, substantially as shown.

The advantages of using the arch in combination with the bridge-wall may be enumerated as follows: First, it causes the entering air to become more thoroughly heated before it is allowed to mingle with the gases, and thus facilitates their rapid combustion; second, it makes alonger run for the gases before entering the tubes or fines, and retains them longer in contact with the heating-surfaces of the firebox; and, thirdly, it insures a more thorough commin glin g of the gases and the air before they enter the tubes. Another advantage arising from the herein-described construction of the wall isthat owing to the fact that its lower end is perforated upon both of its sides, the ascending current of air within it induces a portion of the heated air contained in the ash pan to enter it, while at the same time a current of fresh, cool air enters through the front perforations, and thus an ample supply of air is introduced into the upper portion of the firebox. The front perforations are especially available when the generator is used upon a locomotive, as the forward and rapid movement thereof tends to create a rapid current of air through them, and thus to induce the passage into the fire-box of a liberal supply thereof.

WVe have shown our improvement as applied to a locomotive steam generator; but it is equally adapted for use in astationary furnace or any other generatorin which a fire-box and tubes or fines are used. We do not therefore limit ourselves to its application to any particular type of generators.

Havingthus described our invention,what we claim, and desire to secure by Letters Patent, 1s-

A combined bridge-wall and arch for use in steam generators, containing the followingnamed elements, viz: a vertical hollow portion, A, extending below the grates of the fur nace, it having below said plates apertures for the admission of air upon one or both of its surfaces, an inclined or angular portion, D, having in it a passage for air corresponding with that formed in the vertical portion A, said angular portion extending to near the center of the fire-box, as shown, whereby it is made to deliver the heated air into the ,body of the escaping gases, substantially as and for the purpose set forth.

In testimony whereof we affix oursignatures in presence of two witnesses.

THOMAS CLIFFORD. JAMES CLIFFORD. Vitnesses:

JOHN LAVELLE, N. W. HoWsoN. 

